<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>动画</title>
	<style type="text/css">
		.box{
			width: 100px;
			height: 100px;
			background-color: gold;
			transition: width 500ms ease 1s,height 500ms ease 500ms;
		}
		.box:hover{
			width: 500px;
			height: 300px;
		}
	</style>
</head>
<body>
	<div class="box"></div>
</body>
</html>